ACS Catalysis,
Год журнала:
2024,
Номер
14(20), С. 15790 - 15798
Опубликована: Окт. 10, 2024
Here,
we
report
a
photoredox
and
nickel-catalyzed
cross-electrophile
coupling
strategy
for
the
asymmetric
three-component
1,2-alkylarylation
of
vinyl
boronates
with
(hetero)aryl
bromides
(2°,
3°)-alkyl
redox-active
esters
in
presence
Hantzsch
ester.
With
fluorinated
pyridyl-substituted
chiral
biimidazoline
ligand,
this
reaction
enables
straightforward
access
to
wide
variety
synthetically
valuable
α-aryl
from
readily
available
starting
materials.
This
features
mild
conditions,
broad
substrate
generality,
good
functional
group
tolerance
proceeds
without
using
metal
reductants
or
alkyl
halides.
Furthermore,
alkenyl
halides
other
electron-deficient
alkenes
such
as
acrylates
phosphonates
can
be
applied
successfully.
Preliminary
mechanistic
studies
shed
light
on
potential
pathways
roles
organic
amines.
Heteroatomic
groups
in
alkenes
typically
direct
thermodynamically
favored
chain
walking
of
C═C
bonds
toward
themselves,
thereby
facilitating
C-H
bond
functionalization
near
the
heteroatoms.
We
present
herein
an
efficient
cobalt-catalyzed
contra-thermodynamic
remote
hydroboration
alkenylboronates
with
pinacolborane
to
synthesize
chiral
1,n-diboronates.
This
protocol
features
a
broad
substrate
scope,
high
functional
group
tolerance,
and
excellent
enantioselectivity.
Mechanistic
studies
indicate
involvement
chain-walking
process.
Gram-scale
reactions
various
product
derivatizations
further
highlight
its
practicality.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Март 5, 2025
The
β-H
elimination
is
a
crucial
elementary
step
in
transition-metal
catalysis,
but
controlling
the
stereochemistry
of
this
process
has
been
underdeveloped.
limited
works
reported
so
far
have
only
focused
on
creating
axial
chirality
allenes,
and
no
report
able
to
build
central
using
asymmetric
elimination.
In
study,
we
Trost
ligand-enabled
enantioselective
desymmetric
reaction
from
π-allyl-Pd.
This
transformation
provides
rapid
access
cyclohexenes
bearing
C4-remoted
stereocenter,
total
synthesis
(-)-oleuropeic
acid
(-)-7-hydroxyterpineol
demonstrated.
Computational
studies
shown
that
rate-determining
step,
non-covalent
interactions
between
amide
moiety
ligand
benzene
cyclohexane
moieties
substrate
play
key
role
stereocontrol
during
An
expedient
synthesis
of
α-aminoboronic
acid
derivatives
via
cobalt-catalyzed
remote
site-selective
hydroboration
unactivated
alkenes
is
described
herein.
The
strategy
characterized
by
its
simplicity,
site-selectivity,
and
wide
substrate
scope,
as
both
terminal
internal
could
undergo
the
reaction
smoothly,
affording
corresponding
products
in
good
yields.
According
to
mechanism,
Co-H
generated
from
Co(acac)2
presence
HBpin,
which
starts
chain-walking
a
series
alkene
insertion
β-H
elimination
process.
Herein,
a
nickel-catalyzed,
photoredox
Giese
addition
reaction
with
readily
accessible
alkyl
bromides,
driven
by
available
feedstock
MeOH
as
the
halogen-atom
transfer
(XAT)
reagent,
was
successfully
achieved
under
mild
conditions.
The
versatility
of
this
protocol
demonstrated
through
range
structurally
varied
bromides
and
Giese-type
acceptors
moderate
to
good
yields.
Mechanistic
investigation
highlights
that
formation
radicals
XAT
tentatively
prompted
•CH2OH,
which
derived
from
sequential
photo-oxidation/1,2-hydrogen-atom
MeOH.
Angewandte Chemie International Edition,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 27, 2025
Abstract
Palladium‐catalyzed
cross
coupling
of
enolates—α‐arylation—is
an
established
method
for
chemical
synthesis.
A
major
challenge
in
the
field
is
control
stereochemistry
α‐carbon.
This
typically
due
to
facile
epimerization
under
basic
reaction
conditions
α‐arylation.
In
this
study,
alternative
approach
presented
that
involves
Pd/Cu‐catalyzed
arylboration
electron
deficient
alkenes.
The
products
are
generated
with
high
levels
diastereoselectivity
a
broad
range
substitution
patterns.
Enantioselective
variants
also
addition
product
derivatizations.
Angewandte Chemie,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 27, 2025
Abstract
Palladium‐catalyzed
cross
coupling
of
enolates—α‐arylation—is
an
established
method
for
chemical
synthesis.
A
major
challenge
in
the
field
is
control
stereochemistry
α‐carbon.
This
typically
due
to
facile
epimerization
under
basic
reaction
conditions
α‐arylation.
In
this
study,
alternative
approach
presented
that
involves
Pd/Cu‐catalyzed
arylboration
electron
deficient
alkenes.
The
products
are
generated
with
high
levels
diastereoselectivity
a
broad
range
substitution
patterns.
Enantioselective
variants
also
addition
product
derivatizations.
Herein,
we
report
a
nickel-catalyzed
1,1-carboboration
of
di-
and
trisubstituted
alkenyl
boronates
through
chain-walking
strategy.
This
reaction
effectively
addresses
the
polarity-mismatch
problem
via
ligand
control,
enabling
coupling
various
carbon-based
electrophiles
while
accommodating
broad
range
functional
groups.
The
approach
yields
diverse
tetrasubstituted
carbon
gem-diboronate
derivatives
with
exceptional
regioselectivity.
synthetic
utility
this
method
is
further
demonstrated
concise
synthesis
high-value
bioactive
molecules.
Organic Letters,
Год журнала:
2024,
Номер
26(12), С. 2500 - 2504
Опубликована: Март 18, 2024
We
developed
a
rhodium-catalyzed
chain-walking
hydrothiolation
process
for
internal
alkenes,
which
offers
novel
and
efficient
alternative
C(sp3)–H
bond
cleavage,
while
focusing
on
thiol
incorporation.
This
method
exclusively
affords
N,S-acetals
at
36–90%
yields.
Regioconvergent
significantly
improved
the
effectiveness
of
this
transformation.
Preliminary
mechanistic
investigations
revealed
that
an
amide-directing
group
is
essential
regioselective
synthesis,
underlining
its
significance
in
process.
ACS Catalysis,
Год журнала:
2024,
Номер
14(7), С. 5077 - 5087
Опубликована: Март 20, 2024
1,1-Disilanes
are
synthetically
versatile
building
blocks,
owing
to
their
low
toxicity,
high
stability,
and
unique
structures.
However,
the
practical
synthesis
of
1,1-disilanes
is
still
a
challenge.
Despite
available
Fe-,
Co-,
La-,
B-catalyzed
protocols,
use
highly
reactive
reductants,
such
as
EtMgBr,
NaBHEt3,
or
KHMDS,
inevitably
requires
air-
moisture-free
conditions.
Herein,
we
report
homogeneous
Ni-catalyzed
mono-
dihydrosilylation
aliphatic
terminal
alkynes
under
either
air
water
conditions
neat
conditions,
affording
β-(E)-vinylsilanes
in
yields
with
complete
regioselectivity
stereoselectivity.
Importantly,
our
method
gram-scalable
sole
example
alkynes.
We
demonstrated
introduction
different
silyl
groups
through
stepwise
addition
each
silane
source
reaction
vessel.
Furthermore,
intermediates
were
characterized
spectroscopic/spectrometric
tools,
density
functional
theory
calculations
performed
understand
mechanism
origins
for
1,1-disilanes.
